Thought about thought controlled Bicycle

^ NuVinci. Although it's hardly light.

Anyway. It's a concept, not a marketable innovation. It doesn't matter if it doesn't work in practice the first time around - it's just a test-bed to see if the technology could be refined and put to use (perhaps not for gear shifting, perhaps not even on a bicycle). I'm sure the first time Mr. Benz showed off his automobile, a lot of people said 'Well, horses are faster, cheaper and more reliable, so this 'car' thing is a waste of time'.

They've used CVTs in cars with quite a bit of success, even F1 cars until it was banned. I'm fairly sure it will eventually become a viable option for bikes in the future though.